Recently a process has been disclosed in U.S. Pat. No 5,607,551 issued Mar.4, 1997 to Farrington, Jr. et al. which allows the production of soft absorbent tissue structures without the use of traditional Yankee dryer creping. Sheets produced by this uncreped throughdried process can be characterized as being very three dimensional with high bulk, high absorbent capacity and fast absorbent rate. However, because of the high degree of surface contour, such sheets can also abrade the skin. In addition, while the high absorbent capacity and fast absorbent rate of sheets produced in this manner can be ideal for some absorbent products, soft tissues such as facial and bathroom tissue often find advantages in a more controlled, even slow, absorbent rate while maintaining high absorbent capacity.
While it is known to provide tissues with lotions that can improve softness, the addition of such materials can decrease the thickness of the tissue sheets due to a partial collapse of the crepe structure when exposed to moisture and processing pressures.
Furthermore, the general approach in the industry has been that the greater the quantity of additive on the tissue, the greater the benefit. Contributing to this approach is the fact that particular additives may be absorbed into the tissue, leaving less additive on the surface to provide the intended benefit. One major drawback to the "more is better"philosophy is cost. Additives to address skin abrasion can represent a significant portion of the cost of a tissue sheet. Also, for some additives, relatively high addition levels can be difficult to manufacture.
Thus, there is first a need to enhance sheet softness and/or reduce the potential for skin abrasion with an economical, yet effective, surface additive without losing the thickness of the uncreped throughdried tissue. Secondly there is a need for a cost effective method to manufacture uncreped throughdried tissue products including such an additive.